Improvement in door-springs



tnted tates stent @Nitin-r( WILLIAM Ff KELLS, 0F SAN FRANCISCO, CALIFORNIA."

Letters PatentNo. 108,268, dated October 11, 1870.

IMPROVEMENT IN DCOR-SPRINGS.

The Schedule referred to in these Letters Patent and making part of the im struction and arrangement of a door-spring, with its several attachments for automatically closing a door,

` as will be hereinafter fully set forth.

In order to enable others skilled in the art to which my invention appertains to make and use the.

same, I will now proceed to describe its construction and operation, referringto the annexed drawing, in which Figure l is a side vview cf the door, part in section, showing the spring and its attachments; and

Figures 2, 3, and 4 are det-ached views ofthe spring and its attachments.

A represents the door-frame, and

I, the door, to which my door-spring is attached.

In the upper edge of the door B is made a recess, for the insertion ot' a metallic box, C, the upper plate of which extends beyond the ends of the box, -and is secured flush with the edge of the door by means of two scnews, a a, one at each end.

Through the center of the box G passes a shaft, b, to which the inner end of a coil spring, D, is secured. This spring is wound around the shaft by means that will be presently described, and the other end passes through an opening formed in the end of the box toward the inner edge of thedoor, and moves in a groove formed in the upper edge.

The outer end of the spring D is slotted, as shown in g 4, so as to pass on both sides of the screw a at that end ot' the box C, and to allow the spring to be moved either way.

At the outer end of the spring D is attached a' chain or wire, d, which passes between two friction-rollers e e.

These rollers are placed in a metallic box, E, iuserted in the inner upper corner of the door, and said box has an opening at cach end for the chainor wire (l to pass through.

il-he other end of this chain or wire is hooked or otherwise attached to a pin, j, secured on the inner side of a slotted plate, G, in a Vrecess on the doorframe, the chain or wire passing through the slot in said plate. t

The spring I) is wound up ou the shaft b, byturning said shaft by means of a key, or other convenient m ea11s,`and a pawl, It, pivoted on the side of the box C, engages` with a ratchet-wheel, m, on the shaft b, thus holding the spring at the desired tension.

VVhenthe door is opened the coils of the spring contract, and by the expansion of said coils the door is closed again.

If the spring, by use, should become weaker, it can readily be wound tighter around its shaft, which will at once remedy the defect.

Having thus fully described my invention,

What I claim as new, and desire to secure by Letters Patent, is-

The combination ot' the box C, spring D, shaft b, ratchet-wheel 1n, pawl h, chain or wire d, box E, rollers e e, plate G, and pin f, all constructed as described, and arranged to operate substantially as and for the purposes herein set forth.

In testimony that I claim the foregoing, I have hereunto set my hand this 28th day of September,

\VILLIAM F. KELLS.

Witnesses A. N. Mann, J. E. HUToHINsox. 

